On Thu, Jul 10, 2014 at 06:38:26PM -0400, Bruce Momjian wrote:
> On Thu, Jul 10, 2014 at 06:17:14PM -0400, Bruce Momjian wrote:
> > Well, we are going to need to call internal C functions, often bypassing
> > their typical call sites and the assumption about locking, etc. Perhaps
> > this could be done from a plpgsql function. We could add and drop a
> > dummy column to force TOAST table creation --- we would then only need a
> > way to detect if a function _needs_ a TOAST table, which was skipped in
> > binary upgrade mode previously.
> >
> > That might be a minimalistic approach.
>
> I have thought some more on this. I thought I would need to open
> pg_class in C and do complex backend stuff, but I now realize I can do
> it from libpq, and just call ALTER TABLE and I think that always
> auto-checks if a TOAST table is needed. All I have to do is query
> pg_class from libpq, then construct ALTER TABLE commands for each item,
> and it will optionally create the TOAST table if needed. I just have to
> use a no-op ALTER TABLE command, like SET STATISTICS.
>
> I am in Asia the next two weeks but will work on it after I return.
Attached is the backend part of the patch. I will work on the
pg_upgrade/libpq/ALTER TABLE part later.
--
Bruce Momjian <br...@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ Everyone has their own god. +
diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c
new file mode 100644
index bdfeb90..6e8ef36
*** a/src/backend/catalog/toasting.c
--- b/src/backend/catalog/toasting.c
*************** create_toast_table(Relation rel, Oid toa
*** 165,180 ****
if (rel->rd_rel->reltoastrelid != InvalidOid)
return false;
! /*
! * Check to see whether the table actually needs a TOAST table.
! *
! * If an update-in-place toast relfilenode is specified, force toast file
! * creation even if it seems not to need one.
! */
! if (!needs_toast_table(rel) &&
! (!IsBinaryUpgrade ||
! !OidIsValid(binary_upgrade_next_toast_pg_class_oid)))
! return false;
/*
* If requested check lockmode is sufficient. This is a cross check in
--- 165,211 ----
if (rel->rd_rel->reltoastrelid != InvalidOid)
return false;
! if (!IsBinaryUpgrade)
! {
! if (!needs_toast_table(rel))
! return false;
! }
! else
! {
! /*
! * Check to see whether the table needs a TOAST table.
! *
! * If an update-in-place TOAST relfilenode is specified, force TOAST file
! * creation even if it seems not to need one. This handles the case
! * where the old cluster needed a TOAST table but the new cluster
! * would not normally create one.
! */
!
! /*
! * If a TOAST oid is not specified, skip TOAST creation as we will do
! * it later so we don't create a TOAST table whose OID later conflicts
! * with a user-supplied OID. This handles cases where the old cluster
! * didn't need a TOAST table, but the new cluster does.
! */
! if (!OidIsValid(binary_upgrade_next_toast_pg_class_oid))
! return false;
!
! /*
! * If a special TOAST value has been passed in, it means we are in
! * cleanup mode --- we are creating needed TOAST tables after all user
! * tables with specified OIDs have been created. We let the system
! * assign a TOAST oid for us. The tables are empty so the missing
! * TOAST tables were not a problem.
! */
! if (binary_upgrade_next_toast_pg_class_oid == OPTIONALLY_CREATE_TOAST_OID)
! {
! /* clear it so it is no longer used */
! binary_upgrade_next_toast_pg_class_oid = InvalidOid;
!
! if (!needs_toast_table(rel))
! return false;
! }
! }
/*
* If requested check lockmode is sufficient. This is a cross check in
diff --git a/src/include/catalog/binary_upgrade.h b/src/include/catalog/binary_upgrade.h
new file mode 100644
index f39017c..7aff509
*** a/src/include/catalog/binary_upgrade.h
--- b/src/include/catalog/binary_upgrade.h
***************
*** 14,19 ****
--- 14,22 ----
#ifndef BINARY_UPGRADE_H
#define BINARY_UPGRADE_H
+ /* pick a OID that will never be normally used for TOAST table */
+ #define OPTIONALLY_CREATE_TOAST_OID 1
+
extern PGDLLIMPORT Oid binary_upgrade_next_pg_type_oid;
extern PGDLLIMPORT Oid binary_upgrade_next_array_pg_type_oid;
extern PGDLLIMPORT Oid binary_upgrade_next_toast_pg_type_oid;
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